I believe that both CDXtract and Translator have demo versions. You should try them both out. In some cases, I have found Translator to do a better conversion and in others I have found CDXtract to do a better job. The raw samples sound exactly the same (to me). It is the programs and programming that sound different from time to time. That is why I own both.
CDXtract converts first to an internal format and then converts to any of the destination formats from there whereas I believe that Translator attempts to convert the programs directly. That is why I tend to use Translator more for my conversions and it is the one that I go to first. The user interface is simpler on CDXtract but I find that Translator gets me closer to the original programs quicker.
If the original libraries are simply programmed (many Akai libs are - but not all), either one will work without issue IMHO. Translator tends to work better for me when there is more complex programming such as modwheel crossfades, etc. YMMV.
Sorry, I have no experience with Halion's conversion routines. I recommend that you try Halion's conversion as well as the demos for CDXtract and Translator. Take some basic programs as well as some that have more complext programs and compare the results.